AU2005100826A4 - Trestle-type work platform - Google Patents

Description

03/10/2005 16:46 61-3-98901337 PATENT ATTORNEY SERV PAGE 03/18 3 TRESTLE-TYPE WORK PLATFORM SFIELD OF THE INNOVATION

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o This innovation provides an improved trestle-type work platform.

BACKGROUND

Figures I and 2 show a folding "trestle-type work platform 1 or bench of a k known type that is widely used by tradespersons and homeowners and in industry. Work 00 platform 1 has an elongated work support member 2 and two support frames 3 that are hinged for rotation about hinge axes 4. Each support frame 3 is a planar frame having two legs 5 secured to each other near their upper ends by being welded to intermediate parts 19. As an option, a tie 10 secures legs 5 together at a lower level also. In the working position shown in Figures 1 and 2, support frames 3 are rotated so that their upper end surfaces 7 (which are offset from hinge axes 4) abut support 2. This prevents further outward rotation. Thus, support 2 is stably supported above a surface 6. For storage and transport, support frames 3 are rotated toward support 2 so that work platform 1 becomes more compact. The left one of support frames 3 is shown partly rotated towards its storage position in Figure 1, in phantom lines.

The support 2 is formed from a hollow aluminium extrusion of rectangular crosssection. Such extrusions are nowadays commonly used as an alternative to timber planks, and provide comparative lightness, strength and low cost.

The present innovation relates to improvements in the construction of such work platforms. Refening to Figures 1 and 2, support frames 3 are fabricated from suitable aluminium alloy components (19 and legs 5) by welding, and are journalled on bolts 9 that pass through tangs 8. Tangs 8, of which there are two for each support frame 3, are welded to sides of the support 2. Parts 19 of support frame 3 comprise an obtuse angle aluminium extrusion welded to 2 aluminium strips that act as the hinged arm of support

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COMS ID No: SBMI-01647291 Received by IP Australia: Time 16:47 Date 2005-10-03 03/10/2005 16:46 61-3-98901337 PATENT ATTORNEY SERV PAGE 04/18 O frame 3 and then legs 5 are welded inside this part. Each support frame 3 therefore 1 requires several welds and must be assembled in a suitable jig (not shown) for accurate 0 0 placement of the holes (not shown) through which bolts 9 pass, correct angles of the legs o 5 (which can be seen to splay outwards for stability) and accurate abutting of surfaces 7 against support 2 surfaces 7 should be accurately parallel to hinge axis 4 for each

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Cl support frame 3. Due to the several welds required to form support frame 3 the welding 00 O of parts 19 and legs 5 needs to be carefully done to achieve the required strength of In support frame 3 as well as the correct outward and splay angles to legs 5. Further, the O placement of tangs 8 must be accurately achieved, and care is required in welding them in place so that support frames 3 rotate freely and precisely. The welding of tangs 8 to support 2 must also be carefully done to avoid possible compromise of the strength of support 2.

Although modern welding equipment helps in avoiding distortion and achieving the desired neat and accurate results, nevertheless making a satisfactory product can be quite time consuming and expensive.

The present innovation provides an improved construction which addresses these issues.

SUMMARY OF THE INNOVATION According to the innovation there is provided a work platform comprising a work support member and two support frames, each support frame being rotatable between a working position and a folded position about a hinge axis of that support frame, and wherein: at least one said support frame is hingeably mounted to a bracket; and the said bracket is secured to the work support member by one or more fasteners.

2 COMS ID No: SBMI-01647291 Received by IP Australia: Time 16:47 Date 2005-10-03 03/10/2005 16:46 61-3-98901337 PATENT ATTORNEY SERV PAGE 05/18 O Preferably, a said fastener securing the bracket to the work support member N comprises a fastener a rivet), preferably a fastener of the type that can fasten two 0 parts together without access being required to both ends of the fastener. This arrangement allows the use of for example a hollow work support member extruded from an aluminium alloy, without the need for welding to the work support member, which ION may distort it or compromise its structural integrity. An example of a suitable rivet is the cO 00 Sso-called "Pop" rivet, which is well-known in the mechanical art. Such a rivet is Spositioned in a hole drilled through two parts to be joined, whereupon a special tool that 0 0 requires access only to one end of the rivet is operable to expand the inaccessible end so as to clamp the two parts between the expanded end and a formed head of the rivet.

Another suitable fastener would be what is known in the trade as a "nutsert" wherein a nut is similarly riveted on to one of the parts to be joined and then a bolt is used to join the parts together. It will be appreciated that other types of fasteners can equally effectively be used, e.g. a bolt and nut.

Conveniently, the bracket may comprise a length of channel section material having flanges and a web, the web being secured to the work support member by the said one or more fasteners.

In a particularly preferred embodiment of the innovation, the said support frame comprises: elongated leg members; and connector means to which the said leg members are secured, preferably by fasteners, and which is hingeably mounted to the bracket.

By the use of such connector means the manufacturing of the support frames can be simplified, and in particular welding eliminated.

3 COMS ID No: SBMI-01647291 Received by IP Australia: Time 16:47 Date 2005-10-03 03/10/2005 16:46 61-3-98901337 PATENT ATTORNEY SERV PAGE 06/18 o In a preferred form, the connector means has depending lugs which are receivable C in internal spaces of the legs. Thus for example a leg may be an aluminium alloy 0 O extrusion which is simply slipped over one of the lugs and secured in place by a fastener g such as a rivet. Alternatively the lugs may be hollow, e.g. tubular, so that the legs can be fitted into the lugs.

IC' The connector means or a substantial portion thereof may be formed as a casting.

00 SIn this specification, including the appended claims, the use of the words t) "comprise", comprises", and "comprising" in relation to one or more items, elements, O integers or steps is to be taken to indicate the presence of that or those items, elements, integers or steps but not to preclude the possible presence of other items, elements, integers or steps.

In order that the innovation can be better understood it will now be described non-limitingly by reference to preferred embodiments as shown in the attached Figures, of which: Figure 1 is a side view of a known trestle-type work platform in working position on a surface, with one section shown at larger scale; Figure 2 is an end view of the work platform shown in Figure 1; Figure 3 is a side elevation of a trestle-type work platform according to the innovation, with one section shown at larger scale; Figure 4 is an end elevation of the work platform shown in Figure 3; Figure 5 is a perspective view of a portion of the working platform shown in Figure 3; Figure 6 is a partial longitudinal cross-section of the work platform as shown in Figure 4, the section being taken at station 4 COMS ID No: SBMI-01647291 Received by IP Australia: Time 16:47 Date 2005-10-03 03/10/2005 16:46 61-3-98901337 PATENT ATTORNEY SERV PAGE 07/18 O Figure 7 is a perspective view of a hinge casting for use in the work platform shown in Figure 3.

0 DETATLED DESCRIPTION OF PREFERRED EMBODIMENT SFigures 3 and 4 show a work platform 21 according to the innovation. Platform 21 is of the "trestle" type, and generally similar in form and function to work platform 1,

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Cl having an elongate work support 22 and two support frames 23, each comprising two 00 o legs 25. The legs 25 of each support frame 23 are secured to each other by a connecting t member 31 at their top ends and by a tie 30. By means described below, each support 0 0 frame 23 is secured to support 22 in hinging manner, for rotation about a hinge axis 24 that extends transversely to the length of the support 22. Thus each support frame 23 can be rotated as shown by arrows 32 in Figure 3. In this way, platform 21 can be folded compactly underneath support 22 for transport or storage, and unfolded for placement on a surface 26 and for use. In use of platform 21, support frames 23 take up the positions shown in full lines in Figure 3 so that surfaces 27 abut a bracket 33 secured to support 22.

The legs 25 of each support frame 23 lie in a plane that is offset from its hinge axis 24, so that support frames 23 can swing outward and downward only to the positions shown in Figure 3 before contact between surfaces 27 of support frames 23 and bracket 33 prevents further movement. With support frames 23 in these positions, the support 22 is supported stably when work platform 21 is placed on surface 26 as shown.

Platform 21 differs from platform 1 in several respects. Firstly, instead of support frames 23 being hinge-mounted to tangs welded to support 22 (as in platform 1 support frames 3 are hinged on tangs 8 welded to support they are hinge-mounted to brackets 33 which are in turn secured to support 22 by fasteners, such as rivets, i.e. by means other than welding. This in turn means while the strength of support 2 in platform 1 could be COMS ID No: SBMI-01647291 Received by IP Australia: Time 16:47 Date 2005-10-03 03/10/2005 16:46 61-3-98901337 PATENT ATTORNEY SERV PAGE 08/18 0 affected adversely by welding, support 22 of platform 21 cannot be so affected. Further, cinstead of the tangs and bolt heads rotruding out beyond the sides of support 2 and also Sneeding to be welded accurately to align with the welded hinged arms of support frame 3 C in the case of platform 1, by eliminating the need for welding of tangs, the bracket 33 and 0 each other.

Secondly, support frames 23 are easier to fabricate than their equivalents 3 in platform 1. Instead of legs 25 being connected by parts welded to each, as legs 5 of platform 1 are welded to component 19 which also comprises several component parts welded together, legs 25 are secured, without welding, to a connector 31 as described below.

Figure 5 and 6 show at larger scale how a representative one of the support frames 23 is secured to support 22 via one of the brackets 33. Figure 7 shows connector 31 in isolation.

Connector 31 is formed in one piece by casting in a suitable aluminium alloy, and has two depending lugs 34 that are received snugly in legs 25, which are themselves hollow aluminium alloy extrusions. Lugs 34 have been cast with the correct outward and splay angles to cause the legs 25 to be at the correct angles when secured to lugs 34.

Each leg 25 is secured to one of lugs 34 by one or more rivets 35 (one only being shown) that passes through a flange 36 of lug 34. Rivet 35 is of the well-known type (such as a so-called "Pop".rivet) that can be inserted and secured in place without access to both of its ends being required. A hole 37 is drilled through leg 25 and flange 36, the rivet 35 is inserted using a suitable tool (not shown) and the end placed in the hole is expanded 2s using the tool, so that leg 25 and flange 36 are clamped between the expanded end of 6 COMS ID No: SBMI-01647291 Received by IP Australia: Time 16:47 Date 2005-10-03 03/10/2005 16:46 61-3-98901337 PATENT ATTORNEY SERV PAGE 09/18 n rivet 35 and its head 38. This is much easier than fabricating a support frame 3 by 0, welding.

U Connector 31 has two further lugs 39 each with one of a pair of holes 40 that are 0 positioned in line with each other on what in use of connector 31 becomes the hinge axis 24.

O Each bracket 33 is formed from a short length of aluminium alloy channel-section Smaterial, as best seen in Figure 5. (This is not to imply an limitation in the scope of the G innovation. Other ways of providing a suitable bracket 33 will readily suggest themselves to persons skilled in the mechanical art.) Connector 31 fits between flanges 41 of bracket 33, so that each lug 39 is positioned adjacent to one of the flanges 41. Through each adjacent pair of flange 41 and lug 39 there is passed one of two bolts 29 so that connector 31 is secured to bracket 33. ly suitable use of bushes (not shown) the connector 31 is arranged to be rotatable on bolts 29 to provide the movement indicated by arrows 32.

Connector 31 has a surface 27 that when connector 31 is rotated suitably, contacts web 43 of bracket 33. Although surface 27 is shown as flat in Figure 5, it may have raised ribs (not shown) that actually contact web 43.

One of the lugs 39 has a hole 44 that when the support frame 23 is in its working (unfolded) position aligns with a hole (not shown) in the adjacent flange 41 of bracket 33 so that a locking pin 46 can be passed through both, thus enabling locking of connector 31 and therefore support frame 23 as a whole in the working position. A second hole 47 in the lug 39 that can align with the same hole in flange 41 permits pin 46 to be used alternatively to lock connector 31 and support fiame 23 in another (eg folded or transport) position.

Bracket 33 is secured to support 22 by riveting, again using expanding (eg "Pop'" rivets 50. In this way, welding of the support 22 is avoided.

7 COMS ID No: SBMI-01647291 Received by IP Australia: Time 16:47 Date 2005-10-03 03/10/2005 16:46 61-3-98901337 PATENT ATTORNEY SERV PAGE 10/18 o It will by now be apparent that the construction of platform 21 does not require Sthe use of welding, except perhaps where a tie 30 is simply welded as a brace between 0 legs 25, and that in fact the construction of support frames 23 and their mounting to O support 22 requires less skill than is required to construct platform 1.

Variations to the basic innovation as described are possible without exceeding its

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N essential scope.

0 0 0 8 COMS ID No: SBMI-01647291 Received by IP Australia: Time 16:47 Date 2005-10-03

Claims (4)

1. 3. A work platform according to claim 1 or 2 wherein the said bracket comprises a length of channel section material having flanges and a web, the web being secured to the work support member by the said one or more fasteners.
2. 4. A work platform according to any one of claims 1 to 3 wherein the said support frame comprises: elongated leg members; and connector means to which the said leg members are secured, preferably by fasteners, and which is hingeably mounted to the bracket.
3. 5. A work platform according to claim 4 wherein the connector means or a substantial portion thereof is formed as a casting.
4. 6. A work platform according to claim 5 wherein the connector means has depending lugs which are receivable in internal spaces of the legs or which are receivable over the outer surfaces of the legs. 9 COMS ID No: SBMI-01647291 Received by IP Australia: Time 16:47 Date 2005-10-03 03/10/2005 16:46 03/0/0851646 61-3-98901337 PATENT ATTORNEY SERV PG 21 PAGE 12/18 Dated thils 3- day Of October 2005 2 PATENT ATITORNEY SERVIC.ES, 0 Attorneys for 0 ELVIN DHARMARAJ 00 01 COMS ID No: SBMI-01647291 Received by IP Australia: Time 16:47 Date 2005-10-03